Anal. Chem. 1990, 62, 184R-212R Tam, M.; Ken, M. nlsnfa 1089, 58, 955-6. Ramhandran, R.; Gupta, P. K. tabnfa 1988, 35, 653-4. Qrawo, G.; Bufab, G. At. Spscirasc. 1900, 0 , 84-6. MSu, T.; U n , M. A M M t (London) 1988, 113, 1683-6. Chekraborty, D.; Das, A. K. Anabt (London) 1989, 114, 67-9. Chakraborty, D.; Das, A. K. Anal. chbn. Acta 1989, 218, 341-4. Xu, T.; Xu, B.; long, W.; Fang, Y. Huan/hg Kexue 1987, 8 , 76-8. (199) krtlnez (%nzalez, P.; C a m r a Rlca, C.; Polo Dlez, L. J . Anal. At. SpeCtrom. 1987, 2 , 809-11. (1100) Rodriguez, M. V.; Jlmenez de Blas, 0.; Hernandez Mendez, J. J . Text. Inst. 1988, 70, 409-16. (1101) Hernandez Mender, J.; Jimenez de Blas, 0.; Rodriguez Martin, V. Mkxochem. J. 1988, 37, 275-81. (1102) Heme*z Mender, J.; Jhnenez de Blas, 0.; Lozano Garcia, A. MiCrochsm. J. 1988, 38, 355-60. (1103) Nilwon, C. A.; Nyqen. 0.; Slkstroem. E. chemosphere 1987, 16, 2423-8. (1104) RCk, F. E.; De Beer, P. R.; Mnsloo,S. M.;Van Dyk, L. P. Pes&. Scl. 1087, 21, 45-9. (1105) Montwo, R.; Gallego, M.: Valcarcel, M. Anal. Chlm. Acta 1988, 215. 241-8. (1106) Drasch, G.; Kretschmer, E.; Kauert, G.; Von Meyer, L. J . Fwensic SCl. 1987, 32, 1768-93. (1107) Bezzl, A.: Montgomery, J.; Alent, G. Analyst (London) 1988, 113, 121-4. (1108) D'Hawe, P. C.; Lamberts, L. V.; De Broe. M. E. Clln. Chem. 1989, 35, 884-7. (192) (193) (194) (195) (1st)) (197) (198)
1988, 22, 527-31. (J6) Ebdon, L.; HIII, S.; Watton, A. P.; Ward, R. W. Analyst(London) 1988, 113. - . - .1159-65. (J7)1R-44R. Crwser, M. S.; EWon, L.; Dean, J. R. J . Anal. At. Specawn. 1988, 3 , (J8) Hlckmn, D. A.; Rooke, J. M.; Thompson, M. J . Anal. At. Spectrorn. 1987, 2 , 211R-241R. (J9) Brown, A. A.; Halls, D. J.; Taylor, A. J . Anal. At. Spectrom. 1988, 3 , 45R-88R. (JlO) Kantipuly, C. J.; Westland, A. D. Talenta 1988, 35, 1-13. Table V (J11) Abbasi, S. A. Anal. Left. 1988, 2 1 , 653-5. (J12) Abbasi, S. A. Anal. Left. 1988, 2 1 , 1705-21. (J13) Ivicic, N.; Blanosa, M. Fresenbs' Z . Anal. Chem. 1988, 330, 643-4. (J14) Qulnonero, J.; Mongay, C.; De la Guardla, M. Ann. Chim. (Rome) 1989, 70, 311-18. (J15) Mateo, M. D.; Forteze, R.; Cerda, V.; Baucells, M.; Lacort, G.; Roura, M. The7mOchrn. Acta 1988, 128, 21-30. ( J W Horvat, M.; May, K.; Stoepplec, M.; Byrne, A. R. Appl. Organornet. Chem. 1988, 2 , 515-24. (J17) Shearan, P.; Smyth, M. R. Analyst (London) 1988, 113, 609-12. (Jl8) Macpherson, A. K.; Sampson, B.; Dlplock, A. T. Analyst (London) 1988, 113, 281-3. (Jl9) Shlnohara, A.; Chlba, M.; Klkuchl, M. J . Anal. T o x b l . 1989, 13, 135-40. (J20) Brezezlnska-Paudyn, A.; Van Loon, J. C. Fresenlus' Z . Anal. Chem. 1988, 331, 707-12. (J21) Abbasl, S. A. Anal. Len. 1987, 20, 1697-717. (J22) Alarcon, P.; Alonso, E.; Bentto, Y.; De la Fuente, P.; Vergera, A. Int. J . Envkon. Anal. Chem. 1989, 37, 75-82.
J. TECHNIWC COMPARISONS (Jl) Epstekr, M. S. ACS S m . SW. 1988, No. 361, 109-25. 1988, 12, 162-169. (J2) MaeSWn, J. R.; ROuth, M. W. L a h W ~ h (J3) loelg, G. Trace Ekm. Anal. Chem. M .Bkl., Roc. Int. Workshop, 5th 1988, 1-24.
Emission Spectrometry Peter N.Keliher,**+Hosny Ibrahim,* and Daniel J. Gerth Chemistry Department, Villanova university, Villanova, Pennsylvania 19085
This is the 22nd article in the series of biennial reviews in the field of emission s ectrometry/spectroscopy and is the sixth written b the V i b o v a University author group (AIA5). This year hosny Ibrahim joins us as a coauthor replacing John L. Snyder, Huanan Wang, and Sue F. Zhu, who assisted with the last review. This review article will survey selectively the emission spectrochemical literature of 1988 and 1989. By agreement, however, flame emission publications are reviewed in the section of this review issue entitled 'Atomic Absorption, Atomic Fluorescence, and Flame Spectrometry" authored by James A. Holcombe and D. C. Hassel of the University of Texas at Austin (A6). This follows previous custom. Throughout most of the 198Os,we have been reporting on the important new analytical techni ue of inductively coupled plasma mass spectrometry (ICP-M%)even though, technically, it does not involve optical emission. In 1988, Analytical Chemistry began a new review entitled 'Atomic Mass Spectrometry" written by David W. KO enaal ( A n . This review now includes references to ICPand related techniques. Therefore, we do not cite ICP-MS pa era in this review unless they are part of work comparing I8P-MS with optical techniques. Koppenaal's latest review appears in this issue ( A @ . Because of space considerations, we continue to be particularly selective in our review, and we have not attempted to provlde an all-inclusive bibliography. In this fundamental review, the emphasis is on develo menta in theory, methodology, and instrumentation. Apphations will be cited only if they are of particular importance to analytical chemists and spectroscopists; articles of primary interest to astronomers and/or physicists are not, in general (with some exceptions
in section B), cited. Readers should note that detailed and specific application information is available from Analytical Abstracts, Chemical Abstracts, and also the more specific Atomic Absorption and Emission Abstracts published by the PRM Science and Technology Agency (A9). In addition, the latest Application Reviews issue of Analytical Chemistry contains many recent spectrochemical application references (AIO). The Journal of Analytical Atomic Spectrometry (JAAS) contains a very useful pragmatic section entitled Atomic SpectrometryUpdates (ASU). Typjcal ASUs include reports on instrumentation (A1I ) , atomization and excitation (A12),environmental analysis (A13),and clinical and biolagical materials, foods, and beverages (A14). Since its foundin only 4 years ago, JAAS, published by the Royal Society of themistry, has become a major journal in the field and this is certainly due, in large part, to the Editor, Judith Egan. She is commended for her outstanding efforts on behalf of JUS. In going through the 1988-1989 literature, we continue to use the 'core journal" approach and have selected the following publications as bein most relevant. Most emission spectrometry papers pubfished in these journals are cited in this review: Analyst (London),Analytica Chimica Acta, Analytical Chemistry, Analytical Letters, Applied Optics, Applied Spectroscopy, Applied Spectroscopy Reviews Atomic Spectrosco , Canadian Journal of Spectroscopy (Shemical Geology, C!$C Critical Reviews in Analytical &hemistry, Environmental Science and Technology, Fresenius' Zeitschrift fiir Anal tische Chemie, ICP Informution Newsletter, International J u r n a l of Environmental Anal tical Chemistry, JAAS, Journal of Chemical Education, d h w l o the Optical Societ of America, Journal of Quantitative pectroscopy and ladiative Transfer, Microchemical Journal, Optica Acta, Progress in Analytical Spectroscopy, Reviews in Analytical Chemistry, Review of Scientific Instruments, Science, Spectrochimica Acta, Part B, Spectroscopy Letters,
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'Reprints of this review are available o n re uest. t Present address: Chemistry Department,%aculty University of Cairo, Egypt.
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EMISSION SPECTROMETRY Peter N. KeI1h.r is PToIossor of Anawicai Chemistry at Vilisnova UniversW. He received his A B degree (1962) from st. Michael's Coiiege and MSC. (1987) and Ph.D. (1969) degrees from the University of London. ploiessor Kellher also holds the Diploma 01 Membership (D.I.C.) of Imperial CoC lege. Dr. Keliher came 10 Villanova in 1969 he was promoted to Associete Professor in 1974 and to Professor in 1979. He has published approximately 75 papers in various areas 01 analytical chemistry with an emphasis On Spactrometric techniques. He served as Treasurer of the Division 01 Analytical Chemistw IACSI from 1978 throuah
UniversW 01 Cairo. Egypt. He received ail of his academlc degrees rrDm lhe University of Calm. He was the recipient of a ViSBing Scholar Award from the American Peace Feliowship Program. and lhis aiiowed him lo spend several months in 1989 and 1990 in Professor Kelihsr's labmatory at Villanova. During this time. he did extensive research comparing various smpie intrcduction t e c b
Talanta, and Water Research. Papers published in unreviewed magazines such as Americanllnternational Laboratory, Laboratory Practice, Research and Development, Spectroscopy, etc., are not generally cited. However, where we feel that a publication is of fundamental importance, it is cited whatever the source. We have added Chemical Geology to our list of "primary" journals for the first time this year. 1990 Notes: Beginning in 1990, the name of Progress in Analytical Spectroscopy will he changed to Spectrochimica Acta Reuiews. It will continue to publish high-quality review articles. We note the appearance of a new journal, Journal of Trace Elements and Electrolytes in Health and Disease (A1.5). This will certainly be of interest to readers of this review who are involved with clinical and/or medicinal chemistry. The ICPInformation Newsletter (A16) continues to he the "club" newsletter containing very important information on current trends in atomic spectrometry as well as abstracts of atomic spectrometry papers presented at major national and international meetings. This newsletter is edited by Professor Ramon M. Barnes and, as we have stated in the past, "No emission spectrometry laboratory should be without this important newsletter!!!" We continue to enjoy Mark E. Tatro's Atomic Spectroscopy Advances published in Spectroscopy magazine. Applied Spectroscopy goes to 10 issues per year beginning in 1990. This is the official publication of the Society for Applied Spectroscopy.
Talanta continues to thrive under the new coeditorship team of Gary D. Christian (University of Washington) and David Littlejohn (University of Strathclyde, Scotland). The Januarv 1990 issue is a soecial issue on Multielement Soeclrorhe&rral Anhi>& with guest editors hlarianna A. &srh and Kenneth W.Husrh. Havlor l'ni\,ersity.'I'exaz. There are mwy important articles in this sperinl issue that will rertainly be discussed in the 1992 review of Emission Spectrometry. ~
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BOOKS AND REVIEWS Thompson and Walsh (AI?') published the second edition of their text Handbook of Inductively Coupled Plasma
Spectrometry. There are two additional chapters in this edition. Chapter 11 is on ICP-MS, and Chapter 12 presents comprehensive data concerning calibration standards for a variety of metals and alloys together with detection limits for different elements in these materials. This is a most useful book and is certainly recommended. Moore (A18) recently wrote a hook entitled Introduction to Inductiuely Coupled Plasma Atomic Emission Spectrometry. This book is divided into 15 well-written chapters including important sections on excitation sources (the ICP is compared with other excitation sources), instrumentation, nebulization and sample introduction, analysis, accuracy and precision, internal standardization, plasma optimization, and hydride ICP techniques and future trends. This book should certainly he in the library of all emission spectroscopists. Burguera (A19) edited Flow Injection Atomic Spectroscopy. There are eight chapters in this book covering theoretical aspects, basic components and automation, analytical methods and techniques, separation techniques, and various applications. The book concludes with some statements on current trends in the field. Of related interest, Ruzicka and Hansen (A201 recently published the second edition of their hook Flow Injection Analysis. Valcarcel and Luque de Castro (A211 wrote a hook entitled Automatic Methods of Analysis containing useful information on segmented, batch, and continuous analyzers as well as FIA and robotics. McGraw-Hill has recently published several source books in liekls such as acoustics. chmputer srienre, fluid mechanics, and idid-state physics. The Oplii s .Sr.urrr h h (A221and the Sptxfrosc,opg S m r c p h o k rAZ.?), hoth edited hv Parker, u,iH he of particular interest t o rraders u i this revirw. They hoth provide detailed information on topics surh as the inceractiun of light u,ith matter, interaction uf light with energy fields. light detection and processing, instrumentation and techniques, &r well as a partirularly interezting sertion entitled "mgin oispertra". Ingle and Crouch \ A 2 4 1 rerently puhlizhed a texthook entitled .Spvr/n,rhtvnrrol :lnol~srs. The first six chapters provide useful infnrmntim on thr instrumental aspects of optical ipectrcmetry. The remainder of the houk is dkided into atomic and molecular spectrometry, Chapters 8-1I deal with atomic spectrimetry and are very well dune. The second editiun of Thorne'i Spectroph)srcs (A251 has chupters dealing with atumic and molecular structure. light murces and drtectors. prism spectrographs, diffraction gratings, interferometers, laser and ot her spertrosropies. and spectral line tnformatiun. Hirschfeldrr rt 81. rA2fi1. Muenke-Hlackenhurg ( A X J ,and Measure>(A%) puhlished buoks dealing with various aspects oi lasers. Emteryd rAZYi wrote on exlremely useful book entitled C h ~ n i c aand l I'hgsirol Ano1)sis of Inorganic Nutrienls in Plant, S d , Water, and Air. This book rontains a great deal of informatim on 'pragmatic wet chemistry" and should he pf great use particularly IO analysts in developing countries. I'his hook is puhlished h y the Swedish Univrrsity of Agricultural Sciences and can he ohtained (US$50)tiy writing to the publisher rA291. This book IC highly reconimended fo fltuse uorking in rhrs field. Several analytical Chemistry textbooks published in the past 2 years contain infurmatiun on emission spertrumetry. These inrlude the >eventhedition of Willard et al. (:l,?Oi, the second edition of Christinn find OReilly (A.71). the fifth edition nf Skwg et al. t.4321,and Anal>ficalC/iemis/r~:Prinriplua and Tedtniques hv Harais t.4331. Hadjiioannou et al. W 4 i have recently written l'n,hlem Suli,iny in Ana1)tiral Chemistry. a useful undergradunte analytical rhemistry text. Wolman tA3,j) wrote a practical guide for searrhing the chemical literature. llassart nnd coauthors tA:Xi puhlished k . provides a huuk entitled C'hernomerrirs: A T ~ x l l ~ o o This ANALYTICAL CHEMISTRY. VOL. 62. NO 12. JUNE 15. 1990
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much useful information for chemists interested in this ra i d
growing field. Books on statistics were ublished by Hav%eE
and Crain (A37) and by Miller and Mi&er (A38). Miller and Miller (A39) also recently reviewed basic statistical methods for analytical chemistry. A new revised and expanded edition of The Facts on File Dictionary of Chemistry (A40) lists everything from compounds and elements to equipment, processes, and principles. The appendix contains tables listing atomic masses, hysical constants, elementary particles, etc. T. S. West a n f ( t h e late) H. W. Nurnberg edited a book commissioned by IUPAC on the determination of of trace metals in natural waters (A41). Creaser and Davies (A42) edited a book entitled Analytical Applications of Spectroscopy. In fact, the book is a collection of papers presented at the Spectroscopy Across the Spectrum conference held in Great Britain in July 1987. Dux and Stalzer (A43) published a useful book entitled Managing Safety in the Chemical La bora tory. Several A-page Analytical Chemistry reports are of particular importance to emission spectroscopists. In an extremely well written paper, Carnahan and co-workers (A44) discuss the direct determination of nonmetals in solution using atomic spectrometry. Three plasma-based atomic emission s ectroscopic techniques are compared, namely, Ar- and #e-ICPs and He-MIPS. Recent directions with the He-ICP have focused on reducing plasma noise with a laminar flow torch, applying greater powers to the plasma, and maintainin a tandem plasma. Denton and co-workers (A45) publishe an interesting report on the anal ical utility of hi h-performance charge-transfer device ( TD) detectors. ’#he two modes of charge sensing employed are the char e coupled device (CCD) and the char e injection device (8ID). The authors state that CIDs and 8CDs have t potential to solve challenging spectroscopic problems. TDs offer negligible dark currents, peak quantum efficiencies of more than 8070, low read noises, and wide dynamic ranges. These detectors are currently available from several manufacturers in a variety of formats and sizes that respond over a wide wavelength range. Isenhour and co-workers (A&) reported that intelligent robots represent the next step in laboratory automation, and Dessy (A47) discussed waveguides as chemical sensors. Moerner and Kador (A&) pub!ished an A- age re ort with the fascinating title Finding a S le Mole e in a aystack. There is a discussion of opticazetection and spectroscopy of single absorbers in solids. Barnett (A49)discussed user interface design for analytical instruments and asks the speculative question, Is it art or science? User interface is the collection of keys, displays, screen dialogues, printed output, and protocols that the chemist deals with. The interface works well if it is properly organized and if the designer and user speak the same language. Barnett states that the most important trend in the future will be a reater standardization of user interface desi ns based on t‘i,e direct manipulation user interface style. T te answer to the speculative question seems to be a little bit of both. Liscouski (A50) discussed some issues and directions in laboratory automation, and Sharp et al. (A51) described a generic a proach to robotics in the laboratory. Kingston (A52) descrkd a Consortium on Automated Analytical Laboratory Systems (CAALS) proposed by scientists at the National Institute of Standards and Technolo (NI ST), formerly the National Burean of Standards RBS); Megargle (A53)reviewed recent developments in Laboratory Information Management Systems (LIMS). Cunningham (A54) reported on recent developments on “s ueezed light”. Squeezed light is made by cogenerating lightxeams of particular hasin s and mixing them in a nonlinear atomic or molecuEr met!ium. It is possible that the noise reduction pro rty of squeezed light will lead to significant applications in t e future. Some researchers even suggest that squeezed light might lead to a revolution in o tics comparable to that caused b the laser. Yeung (A55)pubshed an A-p e report entitled ierendipity, Technology, and Challe es in3hemcal Instrumentation. This is based on his awar? address when he received the 1987 Division of Analytical Chemistry Award in Chemical Instrumentation. Y eung’s award address paper is certainly recommended reading. Various special issues of various journals have been published during the past 2 years. It is ap ropriate to begin this discussion wlth a reference to the John%. Ottaway Memorial
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Issue (A56)of the Journal of Analytical Atomic Spectrometry (JAAS) honorin the memory of an outstandin analytical spectroscopist wfose premature passing has sadcfened us all. This special issue contains a foreward written by one of Ottaway’s closest associates, David Littlejohn (A57). The issue also contains reflections and reminiscences of John Ottaway written by a variety of workers. The issue itself contains a series of articles written by researchers closely associated with Professor Ottaway; these include some papers presented at a Colloquium Spectroscopicum Internationale (CSI) postsymposium on graphite furnace atomic absorption, Ontario, Canada (June 28-Jul 2,1987) and other pa ers on atomic absorption and relateitechniques. Some of tgese pa ers are discussed in appropriate sections of this review. T e September 1988 issue of JAAS (A58) contains selected papers from the 1988 Winter Conference on Plasma Spectrochemistry held in San Diego, CA, January 3-9,1988. The foreward to this issue was written by Ramon M. Barnes, Conference Chairman. JAAS has also published selected apers from the 4th Biennial National Atomic S troscopy (BkASS) meeting held in York, England, from E e 29 through July 1, 1988 (A59). This issue contains a plenary lecture by Hieftje (A60) entitled Atomic Absorption Spectrometry-Has it Gone or Where is it Going? Gloom and doom is suggested for AAS as an analytical technique by the year 2000. JAAS has also published a selection of papers presented at the First Rio de Janeiro (Brazil) Symposium on Furnace Atomic Absorption Spectrometry (September 18-23,1988); this same issue contains some papers resented at the First International Conference on Plasma %urce Mass Spectrometry held in Durham, England, September 12-16, 1988 (A61). Spectrochimica Acta, Part B published several special issues during the past 2 years. A special issue entitled Needs for Fundamental Reference Data for Analytical Atomic Spectroscopy (A62)is the proceedings of a workshop held in Scarborough, Ontario, Canada, June 19-21,1987. Another issue entitled Analytical Spectroscopy Highlighted (A63) contains invited papers from the 25th CSI held in Toronto, Canada, June 21-26,1987. Relevant papers are discussed in appropriate sections of this review. Physics and Spectroscopy: A Flamin Interaction was a special issue published in late 1988 (A647 dedicated to Professor C. Th. J. “Kees” Alkemade on the occasion of his 65th birthday. This issue contains a reflective article by Alkemade entitled An Amateur’s Adieu (A65). Sadly, Professor Alkemade passed away on February 25,1989. The special issue, however, stands as a memorial to his work. It includes recollections of his work by Smit (A66),Winefordner and Omenetto (A67), Willis (A68),and Hollander and Smit (ASS)as well as an excellent review article by Hannaford and Walsh (A70) on sputtered atoms in absorption and fluorescence spectroscopy. There is also an article by Greenfield et al. (A711 on the Atomizer, Source, Inductively Coupled Plasma in Atomic Fluorescence Spectrometry (ASIA) system, which involves two ICPs (ICP2). Spectrochimica Acta, Part B very recently published Analytical Atomic S ectrometry: from Furnace to Laser (A72) honoring Dr. WJter J. Slavin of the Perkin-Elmer Corp., the 1988 receipient of the prestigious Anachem Award. This issue contains many important papers on both AAS and AES techniques; appropriate papers are discussed in various sections of this review. The American Microchemical Societ (AMS) continues to give the very prestigious Benedetti-Picher Memorial Award at the Eastern Analytical Sym osium. In recent years, the Microchemical Journal (the oflcial publication of the AMs) has been publishing the award address. In 1987, the award reci ient was Professor David M. Hercules of the University of Jittsburgh, and his award address was entitled Laser Microprobe Mass Spectrometry: The Past, Present, and Future (A73). There is an interesting discussion of ionization processes that can occur with lasers. In 1988, the award recipient was Professor Richard F. Browner of the Geor ia Institute of Technology. His award address was entit ed Interfacing with Aerosols: Concept, Place, and Time (A74). Browner noted that aerosols possess some unique properties that give them a special value for interfacin with many types of analytical instruments. Browner descri es aerosols from their earliest use in flame spectrometry to their present application in state of the art instnunents for trace and ultratrace analysis. (The properties that give aerosols their particular
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value for interfacing bulk li u.id solutions with various detection systems are describe! in Browner's excellent award address paper.) The same issue of Microchemical Journal (A75) contains an absolutely superb paper by Ebdon et al. (A76) entitled Fundamental and Comparative Studies of Aerosol Sample Introduction for Solutions and Slurries in Atomic S ectrometry. The authors have measured aerosol size distriiutions from solutions and slurries that exit various points in single- and double-pass spray chambera from an ICP. A phase Doppler shift laser spray anal zer was used in this work. Loth population diameter a n i percentage volume diameter distnbutions are presented in order to elucidate the mechanisms of aerosol formation, transportation, and loss. It was observed that aerosols formed from 1% (m-v) slurries showed no significant differences from those formed from solutions under the same flow conditions, which suggests that similar formation, transport, and loss mechanisms exist for both. A recent issue of Fresenius' Zeitschri t fur Analytische Chemie (A77) contains the abstracts of p enary and keynote lectures as well as posters presented at the International S posium on Microchemistry (ISM) held at Wiesbaden, a t Germany, August 28-Se tember 1,1989. Another issue contains plenary lectures a n i posters presented at Anakon 89 held in Baden Baden, West Germany, April 9-13, 1989 (A78). Another issue contains selected pa ers presented at the Symposium on Flow Injection Analysis eld in Wurzburg, West Germany, March 2527,1987 (A79). This issue contains an excellent review of the subject by Ruzicka (A80). A special issue of Analytica Chimica Acta has the Proceedings of the 4th International Conference on Flow Analysis held in Las Vegas, NV, A ril 17-20,1988 (A81). Another special issue of Anal tica 8himica Acta is entitled Perspectives in Analytical diemistry Proce of an International symposium in Honour of Dr. A. M. G acdonald on the occasion of her retirement from the editorship of Anal tica Chimica Acta (A82). This is based on a symposium ield in Beatenberg, Switzerland, July 68,1988. We wish Dr. Alison Macdonald well in her retirement. The journal Water, Air, and Soil Pollution has recently ublished a special issue entitled Effects of Heavy Metals in orest Ecosystems (A83). Several papers in this issue may be of interest to readers of this review. A very recent issue of the International Journal of Environmental Analytical Chemistry contains selected pa ers presented at the 18th International Symposium on Environmental Analytical Chemistry held 'ointly with the 4th International Congress on Analytical Jechniques in Environmental Chemistry, Barcelona, Spain, September 5-8,1988 (A84). Even though this issue has a 1990 publication date, it seems a propriate to mention it since it is a s ial issue dedicated to tEe memory a very distinguished analytical of Professor Roland W. chemist and the founding editor of the journal. Important pertinent reviews continue to be published in Progress in Analytical Spectroscopy. Dovichi ( A @ )dismes thermoptical spectroscopy for trace microchemical analysis, and Hwang and Winefordner (A86) reviewed re ression methods in analytical chemistry. In a particularly wefwritten review, Dedina (A87) published a detailed evaluation of hydride generation and atomization for AAS. Many of the statements, of course, are relevant to AES. There is a mathematical description of hydride generation and atomization. Wirth (A881 reported on the status of picosecond s ectroscopy in analytical chemistry, and Falk et al. (A89) escribed some experimental and theoretical investigations on furnace atomic nonthermal excitation spectrosco y (FANES). Matusiewicz and Sturgeo (A90) discussed t t e present status of microwave sam le dissolution and decomposition for elemental analysis. kushaw (A91) recently reviewed hi h-resolution laser-induced ionization spectroscopy, and Stepiens (A92) described magneto-opticrotation in atomic vapors. The definitive review of electrodeless discharge lamps (EDLs) written by Sneddon, Browner, Keliher, Winefordner, Butcher, and Michel (A93) finally, after many years of effort, appeared. The review provides an excellent eneral introduction as to what EDLs are and what they have een used for (most1 for AFS), and a theoretical section is also provided. Detaig are given for the preparation of laboratory-constructed EDLs, and there is also a section on operation of the devices.
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Hershey and Keliher ( A M )recently reported some observations on arsenic and selenium determinations using hydride generation AAS and/or plasma emission spectrometry. There is a detailed description of hydride generation reactions in atomic spectrometry. Two types of interference are noted, valence-state effects and interelement effects, and methods for eliminating (or at least reducing) interferences. Michel and co-workers (A951 reviewed laser-excited AFS in flames, plasmas, and electrothermal atomizers, and Sh published a two-part review on neumatic nebulizers ( A 3 and spray chambers (A97) for I8P s ectrometry. Axner and Rubinsztein-Dunlop (A98) descrged laser-enhanced ionization in flames-a powerful and versatile technique for ultrasensitive trace-element analysis. Williams (A99) discussed a plications of Fourier transform spectrometry in the ultraviogt, visible, and near infrared regions. There is a section on its use with optical emission spectrometry. Kuzyakov and Zorov (A100) reported on prospects and results obtainable using atomic ionization spectrometry. Bohn's review (A101) of optical spectrosco y of condensed-phase interfaces includes an interestin &scussion on optical waveguides and surface enhanced kaman scattering. Katritzky and Offerman (A102) described the development of new microsensor coatings. Their paper also includes a short survey of microsensor technology. Lajunen and Choppin have a multipart review of the analytical chemistry of the lanthanides; their first art compares AAS and AES (A103). Of related interest, Zantipuly and Westland (A104) have a eneral review of various methods for the determination of fanthanides in geolo ical samples. Alarcon and co-workers (A105) recently pubfished a comparison study on the determination of cadmium, chromium, iron, and manganese in natural and waste water by AAS and DCP techniques. Falk (A106) reviewed the role of the atomizer as an inherent part of atomic spectroscopic procedures. The practical performances achieved by various furnaces for AAS and AES, such as tube furnaces with and without platform or probes and cup systems, are compared with each other, and the given physical limitations are discussed. The ZCP Information Newsletter continues to publish valuable reports about meetings as well as some reviews and research papers. Some typical reviews include a review on microwave plasma spectrometry (MIP and CMP) by Dahmen (A107, A108) and a particular1 well done selective review and bibliography of DCPs by Ebion et al. (A109). Marcus produced a status report (A110) on glow discharge techniques for AAS,MS, and AES. Marcus states "it is important to keep in mind that the glow discharge is a complementary source to the atmospheric lasmas: it won't replace the ICP." In a somewhat MompLcal review entitled ICP-AES Today and Tomorrow, Eil'bershtein ( A I l l ) discusses some reasons for the tremendous popularity of the ICP and cites some references to the Soviet literature indicating recent work in the USSR. Greenfield (A1121 presented a progress report on his ASIA system. As noted previously, ASIA employs two ICPs (ICP2): a high-powered &/argon plasma that is used to excite fluorescence in the second (argon-argon) ICP. The source ICP is fed with a concentrated solution of the salt of the element that is to be determined. The sample solution is nebulized into the atomizer plasma. A monochromator, lock-in amplifier, and computer comprise the rest of the equipment. Sneddon (A113)recently published a DCP review that gives a detailed description of the theory and operation of these devices. Some results of various sample introduction techni ues to the plasma are discussed, includin pneumatic ne!ulization, slurry atomization, laser ablation, ekctrothermal vaporization, chromato aphic techniques, hydride generation, and flow injection a n f s i s . Jinno (A114) recently reviewed the application of ICP-dtES as detection systems with various combinations of microcolumn liquid chromatography, and Jin and Zheng (A115) reviewed interferences that can occur in ICP-AES. Schramel (A116)reviewed DCP and ICP techniques for trace-element analysis in biomedical and environmental samples. Broekaert continues to write an instrument column for Spectrochimica Acta, Part B; some typical columns are cited (A117, A118). Spectrochimica Acta, Part B introduced a new feature in 1988, Topics in Laser Spectroscopy (A119), as well as a new column in 1989, News on Fundamental Reference Data (A120). All emission spectroscopists should read Schrenk's magnificent paper entitled Historical Development of High-Energy ANALYTICAL CHEMISTRY, VOL. 62, NO. 12, JUNE 15, 1990
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Excitation Sources for Analytical. Emjssion Spectroscopy (A121). This paper traces the historical develo ment of yh-energy source8 for emission spectroscopyfrom Z e earliest re erences available (early 19th century) to the present. Sources discussed in this review are all powered with electrical energy and include arc, spark, and plasma excitation and their many variations. Walsh (A1221 reviewed the history of the Baird Corp. Since this company has had more than 50 years of independent innovation in spectrochemicalinstrumentation, this report should be of interest to many readers. Coleman (A123) recently published an interesting pers ective on university research and graduate studies in Japan. !bus report is based largely on his experiences during a 9-month sabbatical at Osaka University. Sanz-Medel reported (AI24)on present trends, as well as past tribulations, on analytical atomic spectrometry in Spain. Lastly, we present our 1990 award for the “most fun and useful” publication to read. This year we haue a tie!!!Julian F. %on (University of Massachusetts) wrote a book entitled Anal sis-What Analytical Chemists Do (A125). Although this $bok was written primarily for British readers, it will certainly be useful for students everywhere and for anyone interested in what analytical chemistry is all about. M Kaiser (du Pont) and Alan H. Ullman (Proctor and G a k j have written an extremely interestin report entitled Analytical Chemistry in Industry (A126).k h i s discusses the role of the analytical chemist in industry, quality assurance, methods and technique development, troubleshooting (also called “firefighting”), research or science resource, and miscellaneous analytical roles. There is also a section on criteria for success in industry as well as “thumbnail” sketches of several industrial analytical chemists. We congratulate our awardees.
SPECTRAL DESCRIPTIONS AND CLASSIFICATIONS This year, we have once ain decided to present this section in a completely narrative ormat. Due to the nature of the work involved, it is very difficult to assign a particular paper to a definite category, and while we have attempted to classify the work cited in this section on the bass of its major thrust, some references may not be found where expected. In these cases we beg the readers’ indulgence. OSullivan and Maher (BI)identified lines arisin from the 4 5s transitions in Sr VI and Sr VI1 by focusing &e output o a Q-switched A1 0, laser onto planar metallic Sr targets. From the measurea line widths, they were able to estimate the mean kinetic energy of the s ecies in the plasma. Seaton (B2) calculated the widths anishifts of 42 transitions in lithium-like and beryllium-like ions, including the 2s-2p, 25-3 2p-3s 2 3d, 3s-3p, and 3p-3d in Be 11, B 111, C IV, 0 vfl’and Ni 11. Attar (B3)presents coincidence profiles of 11prevalent concomitant elements on the sulfur emission line at 180.73 nm in the third order. He included Ca, Si, Cr, Ti, Mn, Fe, V, Al, Ni, Mg, and Cu, finding interferences in all cases but Cu. Using optogalvanic techniques, Wang et al. (B4) observed three weak spectral lines corresponding to the 2P7 4d6, 2P1 45 and 2P6 4d”l transitions of atomic Ne in a hollow cathde discharge tube. Simmons et al. (B5) present the Fourier transform spectra (0.015-cm-’ resolution) of the nonresonant 405.&, 368.4-, and 364.0-nm lines and the resonant 283.3-nm line from a Pb hollow cathode lamp. A t a lamp current of 4 mA, all peak shapes fit a Gawian function corresponding to a Do ler temperature of 750 f 30 K. Lakshminarayana and !#etty (B6)obtained a s ectrum of SiSe in a microwave discharge containing d of its tLee known band systems and a large number of new bands in the 40006000-A range. Vibrational analysis showed that these new bands belong to the EIZ+ X’Z system and arise out of the transitions from u = 0-13 levels of the EIZ+state to u = 25-52 levels of the XIZ+ state. Coxon et al. (237)photographed the BIZ+ XIZ+ emission bands of DC1 at 166-240 nm in higher orders of a 10.7-m concave grating spectrograph. Vibronic energies and single valued estimates of rotational parameters were obtained for 56 bands of D%1. Kushawaha and Michael (B8)observed atomic Na lines and emission band systems of N2(A-X), N2(B-A), and N2(C-B) by passing a microwave discharge through flowing vapors of NaN3at 200-280 “C. New tables of the Voi function have been provided by Bakshi and Kearney (B9rThey used a 16000-point profile to gen-
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erate the tables and found up to a 28% difference with existing tables. The accurate determination of temperature and electron densities in plasmas remains of at interest. Van der Mullen et ai. (2310) determined local e ectron densities and tem erature profiles in an inductively coupled plasma using absokte intensities of highly excited Ar states. The electron density profiles were then compared with the results of spatially resolved Stark broadening of the H8 line. This comparison allows the ionizing and recombining parts of the plasma to be distinguished. Bydder and Miller (BI1)developed a relaxation technique that provides a sensitive means of determining directly the temperature ratio T,/ Tg,between the electrons and atomic species in an ICP or other low-temperature Ar plasma. Nowak and Van der Mullen (B12) determined electron density and temperature by studying the distribution of the H8 line and the emission of highly excited states. Deviations from local thermal equilibrium (LTE) were also explored. In a related pa er, Nowak et al. 0313) provide a detailed analysis of an Ar I8P in terms of electron density and temperature. Once again, the Stark broadening of the H8 line was used to obtain the electron density directly, while absolute intensities of highly excited Ar states were measured to provide electron densities based upon an equilibrium assumption. Throu h a comparison of the two results, it was determined thate!t ICP may be thought of as close to LTE under a wide range of conditions. Alandari et al. (B14) measured rotational, translational, and surface temperatures in He, Ar, and 0 microwave induced plasmas. The three temperatures depend upon the nature of the gas (0> He > Ar) and increase with power input and pressure. Workman et al. (B15) determined electron densities in a low-power atmospheric pressure He microwave-induced plasma. The group utilized two H-based methods and two He-based methods in an attempt to ascertain the best method. They found that the use of quasi-degenerate He neutral lines possessin forbidden and allowed components afforded electron fensities similar to those obtained via Balmer 8line-shape analysis. Nakahara et al. (B16)evaluated temperatures as a function of radial position, power, and He flow rate in He microwave-induced plasmas produced in an annular-flow torch. He was used for excitation temperatures, and OH for rotational temperatures. Marshall and Hieftje (B17)used mutichannel Thom son scattering in a low-flow, low-power ICP to determine \oth electron densities and electron temperatures. Electron concentrations agree with previously determined values, and the measured spatial variations were consistent with existing models of the ICP. In an extension of the above work, Huang and Hieftje (B18) have developed a new, more accurate procedure for determining electron densities and temperatures utilizing Thompson scattering data. Theoretical background and experimental data are presented. Nowak et al. (B19)determined electron densities using both highly excited Ar states and Stark broadening of the H, line in an investigation of LTE in an Ar ICP. Their investigation also indicates that the plasma is close to LTE. Bydder and Miller (B20)used their relaxation technique (BI1) to show that the excited states (4p and higher) are in partial LTE out to a radius of 7 mm. In the central region, they found that the plasma is in kinetic equilibrium with the gas temperature and within 3% of the electron temperature, with T,i= loo00 K. Lawson and Peacock (B21) discuss the effect of the instrument function on Doppler ion temperature measurements. They demonstrate that the shape of the instrument function of the spectrometer can have an effect on the measured values, even when the broadening is larger than -10 times the half-width of the instrument function. Lu et al. (B22)examined the feasibility of using double Langmuir robes to measure electron temperatures in an Ar ICP. TReir measurements were comparable or higher than n, values calculated from the Saha equation at the measured Te)s. Ishii et al. (B23) measured Abel-inverted excitation temperatures for Ar-N2 ICPs. The dependence of temperature on gas com osition, forward power, observation height, and injector gas [ow rate was studied by using Fe as the thermometric species. Raeymaekers et al. (B24)determined radially resolved rotational temperatures of a 2-kW ICP with Ar, N2, and O2 as outer gases, using N2+and OH as thermometric species. Joshi et al. (B25)measured excitation temperatures and electron
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densities at various heights above the load coil in an Ar ICP. The excitation profiles show an off-axia peak that was related to skin depth. Steers and Leis (B26) rovide us with some observations on the use of a microwaveted glow discharge lamp (GDL) and the relavant excitation processes. In use with co per samples, they found that the changes observed in the u I1 spectrum are consistent with the excitation of upper levels by charge transfer, and for Cu I, ion recombination is the major source of excited atoms. Volkova et al. (B27)studied the population and destruction of the 5p012, 4%' ,5'P1, and 41D2 states of the Sr atom in He discharge in a%ollow cathode. Rates obtained agreed satisfactorily with theory. Rall et al. (BB)measured the apparent cross section for electron-impact excitation out of the 23Smetastable level of He to the 3%, 43S, 33P, 33D, 4 9 , 53D, and 63Dlevels by a novel method. A beam of metastable atoms from a hollow cathode discharge was crossed by an electron beam of variable energy, and the emission from the excited states was detected. Direct electron impact cross sections for the 33P, 33S, and 33D levels were obtained. Piyakis and Gagne (B29)postulate a hybrid Penning char e-transfer reaction for the enhancement of U I11 emission %ymixtures of He and other rare gases in a hollow cathode discharge. They observed that the U I11 emission intensities increase when the ionization potential of the heavier gas decreases. The strongest intensities were obtained with a He-Xe mixture in a 1OO:lratio at a total pressure of 600 Pa. In a similar vein, Wagatsuma and Hirokawa (B30)studied the variations of the emission intensities of s uttered particles when He gas is introduced in AI or Ne glow &charge plasmas. They obtained maximum emission intensities with a 1:lHe:Ar mixture, and noted that the intensity enhancement is more marked as the emission line originates from the transition among energy levels having higher excitation energies. The effect is explained as resonance collisional energy transfer between He ions and sample atoms. Smith et al. (B31)observed the laser-induced fluorescence of NCN downstream of a microwave discharge of N2 and CF4 in He via the A3n,-X32 - transition near 329 nm. The zero-pressure fluorescence fifetime of the 000 vibrational level of the A state was measured from the time-resolved laserinduced fluorescence to be 183 f 6 ns. Lutz et al. (B32) investigated the spectroscopy and dynamics of single vibronic n = 0,1, 2) of propynal levels of the tri let state TI (nr, (HCCHO and 8CCCDO) using direct laser excitation in a free jet. They present a design for an optical detector capable of observin emission decays for up to 200 ps in a jet a paratus. Lo et al. fB33)developed a microwave discharge in a 80Clz/Ar mixture as a source for kinetic studies of the SO(A3rI,,lJ states in a flow reactor using the laser-induced fluorescence method. The radiative lifetime of SO(A3110,1u' = 0) for a 300 K Boltzman distribution of rotational an8 spin-orbit states was found to be 35 f 3 ps. Quenching and spin-orbit relaxation rate constants were also determined. Arndt et al. (B34) measured the lifetimes of several atomic levels of Am I that are connected by electric dipole transitions to the ground state. The Am atoms were excited by li ht pulses from a continuthe aid of an optoacoustic ous-wave sin le-mode dye laser modulator. bransitions homologous to the stron Eu I transitions from the y8P, terms to the grounlstate were observed. Shade et ai.'&d5\ determined radiative lifetimes of 11 Ar I1 and Kr I1 levels using selective pulsed-laser excitation and time-resolved observation of the reemitted fluorescence. The results are discussed with regard to trends in the behavior of lifetimes along homologous series. Garcia and Campos (B36) determined relative transition robabilities for 64 lines arising from excited triplet levels of r I from emission line intensities in a hollow cathode discharge. A comparison was made with previously published data and theoretical studies. Kapoor and Saskena (B37) describe a simple technique to measure relative transition probabilities based upon a line absor tion method. The absorption measurements are performetwith the use of a single hollow cathode disharge, which serves as a light source as well as an a h r p t i o n cell. Omenetto et al. (B38)used fluorescence dip spectroscopy to determine the spontaneous transition probabilities of the Na 2P1/z-.2D3/2 (568.263. nm) and P3/2-'D5 23/2 (568.820 nm) transitions. The ratio between the gA vafues obtained are compared to values calculated from tables. Rodriguez and Campos (B39)determined the relative
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transition probabilities for 173 lines in the 2000-3000-A region of the C1 I1 spectrum. The results were compared with previously published data. Whaling and Brault (B40)have published a comprehensive (and they do mean comprehensive-2835 lines!) listing of transition probabilites for the 2548-10565-A region of the Mo I spectrum. A combination of methods was utilized to completely identify all the transitions involved. Guthoehrlein and Keller (B41)utilized Dop ler-limited optogalvanic spectroscop in a dc hollow catho e discharge to study the blend of the J o I 645.023-nm line. The hyperfine structure constants, frequency difference between the line centers of ravity, and the integrated intensity ratio of the two coinciient transitions were determined. In a similar fashion, Reddy and Rao (B42)also utilized optogalvanic spectroscopy to study the hyperfine structure of Pr. About 78 atomic transitions of Pr I and 43 transitions of Pt I1 were identified, and estimates of relative line intensities were tabulated in the 5760-6250-A spectral range. The hyperfine splitting of the levels involved was large enough to allow determination of splitting constants for both the lower and upper levels. Cheval et al. (B43)analyzed the C4Z--X4Z- (0,O) band of NbO with a high-resolution grating spectrometer. The band structure, and in particular the 93Nbhyperfine splitting pattern are discussed in great detail. A high-resolution Fourier transform spectrometer was used by Manning et al. (B44)to resolve the structure of the B2Z,,+-X Z : transition of Nz+(0,O) at 391.4 nm. This transition is of interest because it is widely used by spectroscopists to calculate rotational temperatures in plasmas and flames. A He-ICP torch was used as an excitation source. Line-Broadening Effects: Measurement and Theory. The study of spectral line broadening phenomena remains of great interest. Fell et al. (B45) measured the collisional broadening and shift parameters of the X'Zg+ A'Z transition of Liz usin Doppler scanning techniques and g e as the perterber as. 6eza et al. (B46)determined the velocity dependence of t i e collisional broadening of the 40Ca4s2 'So 4s5p 'P1 4s17d 'D transition by N atoms. The experiment was performed gy exciting one velocity group of Ca atoms within the Doppler profile of the first transition and probing this group with a counterpropagating laser beam inducing the second transition. Iglesias and Griem (B47) measured the line profiles of the An = 0, n = 2 lines of C V produced when a AlzO :Cr3+ laser was focused onto a polyethylene target. Calcufated line profiles were narrower than the experimental values. Oza et al. (B48)studied the effects of the reduced mass of the radiator and ion perturber ( p ) and electron density temperature on ion broadening of L,, H ,P,, and L, for neutral H radiators. The ion dynamics o? the systems are discussed in detail. Dense plasmas were studied by several workers. Marangos et al. (B49)measured He I1 Balmer series line shapes and shifts, using both emission and absorption techniques, in a dense, cool, He z- inch plasma. Emission measurements were made on the He f1 Balmer-@line profile. Hou and Li (B50) calculated the Lyman line profiies (n 1)of H-like ions using Hooper's first-order theory. Application of the results to plasma diagnostics was discussed. Banon et al. (B51) calculated the s ectral line broadening for the (2p2)'D (ls2p)'P and (2s2p)PP (ls2s)lS dielectronic satellite transitions of the Al He-like emitter in hot and dense plasmas. A discussion of the effects is presented, with particular emphasis on the a pearance of the electric-dipole forbidden dielectronic sate h t e lines. Koshelev (B52)presents calculations that show that the presence of dielectronic satellites present in a spectrum may be responsible for the line asymmetries reported in the literature. Examples are taken from the 2s-3p and 2p4d lines of the F VII spectrum and their satellite transitions 2snl-3pnl and 2pnl-4dnl of the F VI spectrum. Aferenko et al. (B53)have extended the use of Stark diagnostic methods to moderately dense H and He plasmas. The numerical results obtained for H agree with experiment significantly better than previous taeories. Rao et al. (B54)utilized Stark line broadening results to characterize a low-energy plasma. The device consisted of a squirrel cage electrode enclosed in a glass vacuum chamber filled with H2 at a pressure of 2 mbar. Emission in the range 4000-6000 A was monitored. In a theoretical study, Lyublii et al. (B55)treated the Stark broadening of Lyman lines in a high-density plasma. Of
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EMISSION SPECTROMETRY particular interest were the effects of the fields inside the lasmas, the microfield, and the oscillating fields from Eangmuir wava. Basha and Abdel-Ad ( B 6 )measured the half-width and shift of some Stark broadened Ar I lines in a highly stabilized arc. They discuss the suitability of the 43004 Ar line for use in determining electron density in Ar lasma sources. Shah et al. (B57)modeled time-dependent aser-produced spectra formed on a C surface by combining blast wave theory, ionization as described by the Saha equations, and the charge conservation equation. Good agreement was found between theoretical and experimental time-dependent, normalized, l i e intensity profiles and Stark shift profiles. Vu’icic et al. (B58) measured the Stark broadening of the d e I 2lP-3ID (A = 667.8 nm) line. Comparisons to theory were favorable except for the red asymmet ,which was much lower than predicted. Hirose et al. (85~measuredthe spatial variation of the spectral width of the Ar 7d[5/2]3-4~[3/2 2 transition inside the cathode fall region of hollow catho e discharges by laser photovoltaic s ectroscopy. A complicated correlation with the s atial Attribution of the electric field was uncovered. Musiofet al. (B60)tabulated the Stark widths and asymmetries of 10 Ge I lines observed in a wall-stabilized arc (Ne= 5.7 X 10l6cmJ and T = 12450 K). Gavrilenko et al. (B61)calculated the spectral line rofiles of Fe”+ for a plasma of electron concentration 108-10n cm”. The wave functions of the Hamiltonian were represented as expansions on functions of LS coupling. vlesias and Griem (B62)measured space-and time-resolved pro des of Ha,HB,and L6of C VI. Results are discussed from an ion-dynamics stand int, the time-integrated spectra that support the time-resored observations are presented. The Stark widths of seven Ar I transitions in an atmospheric dc argon plasma jet are reported by Bakshi and Kearney (B63). The experimental values are up to 45% smaller than those predicted by Griem’s theory of Stark broadenin and uncertainties in the results are estimated at 110%. Bobilarov et al. (E641have m e a s d the Stark widths of neutral He lines in H-He, pure He, and Ar-He plasmas. The experimentally obtained widths and shifts are compared with theoretical results obtained from three sets of semiclassical calculations using quasistatic and ion-dynamic treatments. GrossmanDoerth et al. (B65)have derived expressions defining the contribution functions of the line depression Stokes profiles formed in a general ma etic field. A computer code for calculating the various g k e s contribution functions is described, and some exam le calculations are presented. Zhang et al. (J366)list the Star&broadening functions of the Balmer lines for the series members 530. The S(a,a) values were calculated for the joint action of the P. J., Holtsmark fields, and turbulent fields. Yang and Barnes (B67) describe a modified Abel inversion technique for lime-width calculation based on the relationship between the lateral and radial line profile in a cylindrical light source. The errors involved in the improved technique ara also discussed. Rees et al. (B68) discuss two numerical methods for formal inte ration of the polarized radiative transfer equations in a 8eeman-s lit line. Contribution functions for the Stokes parameter !ne profiles and line depressions are computed, and the depth of formation of magnetically split lines is discussed. Calisti et al. (B69) investiated the ion-dynamic effects on the line shape of the neutral h e 4471-A line usirq a computer simulation. The results are discuased in comparmn with calculations based on the static ion approximation and with results including ion dynamic effects treated by the model microfield method or a generalized collision operator approach. New methods of spectralanal is utilizing Fourier transform techniques are still being devegped. Van Veen et al. (B70) have developed a deconvolution procedure utilizing Fourier transformation to reduce the line overla in ICP emission spectrometry, while Damarowsky and GutRoehrlein (B71)use a Fourier integral transformation coupled with an iterative least-squares procedure. The latter will allow spectral analysis without the knowledge of the line-shape function. Woltz and Hoo er (B72)have developed a theoretical formalism to calcukte the s ectra of multielectron emitters in plasmas. Calculated Li-eke and Be-like Kr spectra are compared to ex rimental s a obtained in laser implosion experiments. G t n y and rablec (B73) examine the errors
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involved in calculations of Lorentz and Doppler broadening. The influence of normally distributed noise on the calculations is also tested. Lee (B74) describes a simple set of com uter programs that may be used to calculate line shapes for s e f d transitions of H-, He-, and Li-like ions. The programs may be run on either main frame or desk top computers with comparable accuracy. Frerichs (B75)simulated various model processes with calculations based upon the method of model microfields. Results for Lyman-a are shown. Chan and Montaser (B76) developed a new algorithm for the calculation of electron density via least-squares fittings of spectral lines to theoretical Stark broadened profiles. Advantages of the new method over present methods are discussed. Gravelle et al. (B77) measured electron number densities for ar on ICPs at pressures between 120 and 760 Torr. They fountthat at atmospheric pressures, the plasma was in LTE but at ressures
